Concrete slab making machine



Aug. 24, 1965 c. Y. STRONG CONCRETE SLAB MAKING MACHINE 6 Sheets-Sheet 1 DM MN Filed Dec. 24, 1962 INVENTOR C'OlE STRONG.

ATTORNEY.

Aug. 24, 1965 c. Y. STRONG CONCRETE SLAB MAKING MACHINE 6 Sheets-Sheet 2 Filed Dec. 24, 1962 ILEEZ mNN 3 LEE INVENTOR c045 x sreo/vq.

ATTORATY i N\N MN MWN EN 1 NM MN NWN N 6 Sheets-Sheet 3 Aug. 24, 1965 c. Y. STRONG CONCRETE SLAB MAKING MACHINE Filed Dec. 24, 1962 Q m 0b wN INVENTOR. C045 y STRONG.

ATT0RJVJE'X mN gwnnnv wl wh wN aw nw mw Qm QM Aug. 24, 1965 c. Y. STRONG 3,201,845

CONCRETE SLAB MAKING MACHINE Filed Dec. 24, 1962 6 Sheets-Sheet 4 INVENT OR. C015 X STRONG.

LSYQQM ATTORNEY.

Aug. 24, 1965 c. Y. STRONG 3,201,845

CONCRETE SLAB MAKING MACHINE Filed Dec. 24, 1962 6 Sheets-Sheet 5 I N VE N TOR. 6045 x STRONG.

Aug. 24, 1965 c. Y. STRONG CONCRETE SLAB MAKING MACHINE MNN & m mm OW e r 6 m w w Filed Dec. 24, 1962 ATTORNEY United States Patent ()fiice 3,201,845 Patented Aug. 24, 1965 3,201,845 CONCRETE SLAB MAKING MACHINE Cole Y. Strong, Denver, Colo., assignor to Consolidated Industries, Inc, Denver, (3010., a corporation of Colorado Filed Dec. 24, 1962,'Ser. No. 246,728 3 Claims. (Cl. 25-41) This invention pertains to concrete slab making machines and particularly to a' machine adapted to make concrete slabs for forming grave vaults and the like.

,One of the objects of this invention is to provide an automatic machine for making concrete slabs.

Another object of this invention is to provide a machine for automatically forminga series of concrete slabs, one on top of the other to form a sandwich-like pile on a pallet for handling and storage.

A further object is to provide a concrete slab making machine capable of forming a plurality of accurately dimensioned slabs vertically sandwiched one on top of the other to a desired height and number as required.

It is also an object to provide apparatus for forming sandwiched stacks of concrete slabs incorporating reinforcing mesh intermediate the thickness of the Slabs.

A further object of this invention is to provide a machine for automatically forming a series of horizontally stacked concrete slabs which can be varied in size and shape configuration to suit the product which is to be utilized.

Further features and advantages of this invention will appear froma detailed description of the drawings in which:

FIG. 1 is a plan view of a concrete slab making machine incorporating the features of this invention.

FIG. 2 is a side elevation of the concrete slab making machine shown in FIG. 1.

FIG. 3 isa vertical longitudinal sectional view on the line. 3-3 of FIG. 1. z

FIG. 4 is a vertical transverse sectional view on the line 44 of; FIG. 1.

FIG. 5 is a fragmentary diagrammatic view showing the initial forming ofa concrete slab on a pallet by the machine.

. .FIG. 6 is a fragmentary diagrammatic view similar to FIG. 5 butjshowing the completion of the formation of the stack of-concrete slabs.

FIG. 7 is an enlarged sectional view on the line 77 of FIG; 4.

' FIG. 8 is an enlarged sectional view on the line 88 of FIG. 7. FIG. 9 is a circuit diagram of the operating and control mechanism of the machine.

As an example of one embodiment of this invention, there is shown a concrete slab making machine comprising a main support 14, a plurality ofrectangularly spaced vertical columns 15 having floor flanges 16 rigidly fixed thereto and rigidly bolted to the surface 17 of a suitable floor 18 by the bolts 19, as best seen in FIGS. 1, 2 and 7. Guide tubes 20 arevertically slidable on each of the columns 15 and are rigidly connected by the support blocks 21 to the vertical corner members 22 of the frame 23 which includes the end tie bars 24 fixedto the tops of the vertical corner members 22 and the longitudinal upper tie bars 25 interconnected rigidly betweenthe end tie bars 24. Near the lower ends ofthe vertical corner members 22 are fixed the lower end tie ,bars 26 and to. which are fixed the. lower side tie bars 27, FIGS. 3 and 4. The frame 23 is caused to maintain parallelism of up and down level movement on the columns 15 by apparatus comprising a pair of horizontally disposed shafts 28, which are interconnected for synchronous rotation by a chain 28a operating over sprockets 29a fixed to the shafts 28, FIGS. 1 and 4, suitably journaled in bearings 29 on top of the columns 15. Sprockets 30 are fixed to the shafts 28 at the top of the columns 15 over which operate the leveling chains 31, one end 32 of which chains are suitably dead ended or fixed by a suitable bolt 33 to integral lugs 34 of the guide tubes 20. The other ends 38 of the chains 31 pass over idler sprockets 35 journaled on suitable pins 36 carried in slots 37 in the bottom of the columns 1-5 and are connected or dead-ended by bolts 39 to the integral lugs 34a of the guide tubes 20. By this arrangement the frame 23 may move up and down on the columns 15 while maintaining exact parallelism with the floor surface 17.

The frame 23 may be locked in any vertical position on the columns 15 by fluid pressure actuated brakes 40, best shown in FIGS. 7 and 8, located on the lower ends of the tubes 20 comprising the integral brake sleeve 41 having the enlarged counterbore 42 in which are retained the brake shoe segments 43 and 44 and confined therein by the flange 45 held in place by the bolts 46 passing through the integral flange 47 of the guide tube 20, the shoes 43 and 44 having axial end clearance between the surface 48 of the counterbore 42 and the surface 49 of the flange 45 so that slight radial movements of the shoes relative to the counterbore 42 and the surface 50 of the columns is present. An actuating plunger 51 is axially slidable in the radially disposed bore. 52 with its inner end 53 engaging the outer diameter 54 of the brake shoe segment 43. A fluid pressure chamber 55 is formed in the. bore 52 behind the plunger 51 to which is connected suitable fluid pressure supply 1ines 56 so that when pressure is applied in chamber 55 behind the plunger 51 the brake shoes 43 and 44 will be clamped to the columns 15 to hold the frame23 in desired vertical position on the columns 15. i

Rigidly fixed to and depending downwardly from the lower'side tie bars 27 is the mold box 57 having the sides 58 and the ends 59 having'the hinged lower portions 60 hinged at 61, FIGS. 2, 3, 4 and 6, to the lower edges of the ends 59. Suitable releasable clamps 62 interconnected between the sides 58 and the hinged ends 60 serve as releasable means to secure the hinged ends in downwardly swung vertical closed position with the mold box sides 58.

Fixed to the frame 23 and to the'mold box ends 59 are the feed drawer platforms 63 and 64 each having a suitable support frame 65 to which is fixed the deck plates 66 and 67, FIGS. 3 and 5, located in the plane 68 of the top edges of the sides 58 and ends 59 of the mold box 57. Adapted to slide back and forth between the deck plates 66 and 67 across the top edges 68 of the mold box is the feed drawer 69 consisting of an open bottomed box having the sides 70 and the ends 71 and 72. The bottom edges 73 of the sides 70 and ends slide across the top of the deck plates- 66 and 67 and the top edges 68 of the mold box. Suitable guide clips 74 fixed to the sides 70 of the feed drawer and engaging the side edges of the deck plates 66 and 67 and the sides 58 of the mold box serve to maintain lateral alignment of the feed drawer over the deck plates and mold box during its longitudinal sliding movements.

The feed drawer 69 is reciprocated by fluid pressure by a suitable fluid pressure cylinder 75 carried on the frame 23 on one side of the upper portion of the mold box 57 having a piston rod 76 extending out both ends of the cylinder, FIGS. 1, 2, 4 and 9, to which are connected the chains77 and 78. The chains 77 passes over an idler sprocket 79 journaled on a suitable stud 80 carried in the support bracket 81 fixed to a vertical corner member 22 of the frame 23. The other chain 78 operates over a sprocket 82 fixed to a drive shaft 83 journaled in a bracket 84 fixed to a vertical corner member 22 of the frame 23. The outer ends 85 and 86 of the respective chains 77 and 78 are interconnected by the link 87.

Fixed on the drive shaft which operates the chain 89 which in turn operatesover the sprocket 90 fixed to theshaft 91 journaledv in, the frame 65 of the deck plate 67. -iThe shaft,9 1..extends out each. sideof the frame6 fand has fixed thereon the sprockets 92; over which operate the endless feed drawer 83 is the sprocket 88 over I threaded and have suitable adjustable thrust nuts and washers 145 adapted to engage the top surface146 of the stop bars-143 to limit the downward relative position of the pressure plate to the frame 23. The upward relative positio'n'of the pressure. plate is determined by the bottorning of the. pistons 147. in upper position in the, cylinchains 93. The other ends, of the chains. 93 are carried On sprockets 94 fixed'onthe ends of a shaft 95 journaled in the frame -0f the deck plate 66. Suit ableclarnp devices 96 'fixedfto the 'sidesl70 of the" feed drawer, 69 are adapted'to grip the upper span of the endless chains; 93,.

The cylinder is ene'rgijzedfrom a,'suitable source' of. fluid pressure such as the fluid'press'ure pump 97,' FIG 9,

having a suction'1ine198 connected toa reservoir 99 of fluid 100. High pressure discharge rmmthe pum pr passes through pressure line101 into a suitable'accumu- V lator 102.? Discharge frorn'lthe accumulator 102 passes described in further detail as any suitable commercially available vibration will sufiiees through pressure supply .line 103 which is; connected'to the feed drawer control valve 104havinga'return drain line .105. connected into the ;r e servoir .The. control valve 1041s connected by lines 106 and 107 to the cylinder 75 so that by manipulating the control yalve-handle 108 of the: valve ,104QtheIpiston} rod 76 may be recipro- I cated and through the connectedtransmission; 'the reed,

box reciprocates as requiredduring the. operation of the machine. I

. The operation of the cylinders113 controlled by the reversing valve 153, .FIG. .9, which receives a pressure supply from the line 103 and has a return drain line 154 toithe ;reservoir 99.'5 The top charnbers 155 'of the cylinders 113 are; conuectedby thecoinmon line 156 to the'control valvegl53 while the lowerchambers 157 of the cylinders 113 are connected by the common line 158 to, the control valve 153 7510, that by manipulating the control valve'handle 159 fthe fcylinder-scan be energized to raise and, lower the pressure plate' 109 relative to the frame'23.

" sure chamber. 161 which is connected :to the line 156 A ressure plate was mos-nearer vertic l-relative I movement on the frame' 23 The pressure platev 109" has edges 110 which'ar'e'ar'ranged to; fit closely within] the i interior surfaces of 'the 'sidesI58} and ends 59560 ofpthe mold box '57. j The pressure plate 109 isffi-xefdto the lower ends, 111 ofthefpiston'rods' llz fof the-{vertically disposed fluid pressure cylinders 113, ,FIGS; 1,.2;-4 andl9;

' which have theirupperjends'fl l' pivotally connected to a :shaft 1 15 whichfis .fixedin Jthe -brackets116 'fiXed to the upper tie bars 2516f the frame 23;

. -In order tomaidtaifi jexact. pf'r'allelisrn .of'itlie bottoin surface 117 or. the pressure" fplate ,;;109with the plane 68 of the top edges of the mold box- 57,-and 'the floor surface 17 when the cylinders 113 arefenergized-tofvertically i'ela tively' move the, pressure plate 109 andtlie frame 23, there is provided the links 118 which varje'pivotally connected at their'upper ends by pins 119'carried1ii1 suitable mack-- ets 1 20 fixed to the, amide rac s ofithesufiperitie .bars 25 'of:'thefra'me 2s. Thelower end or the ljriks 118 are pivotallyconnected by .a 121' tothe.outenendsgof lever 'arrns122-fixedto. theouter ends .ofthe shafts 123. which are journaled insuitable brackets i 12.4 fixed {to the upright supports. 125. inj tu r'n fixed at, their, 1ower; ends to the supporting name-1 25mm to. th'e to'p' surface 127 b of and adjacent the edges -1f10..ofv thepressure pla't'e10'9.

The'shafts 123 are interconnected fo'r'synchronized 'angu identical sprockets 129 fixed adjacent the. brackets 124 on shafts 123. Laterally spaced links 130 straddle, the chain 128v and interconnect the ends 131 of, the chains' 128'.

Longitudinal horizontaljpositioning of thepressure plate 109 is maintained by 'roller'sf132 journalefdion"pirisj133. carried onframe'members134 fixedat their. inner ends to the upright s'upportsf12'5 and near their :outerends to ti'e.

pieces 135;fixed at theirlojwer. ends to the support frame 126 of 'the'pressure plate" 109;;nem11er 132friding u p and down againstthe surfaces 136 of 'the-verticalf'corner' members 22,.FIGS. 2 and 3'. j Lateral, horizontal position:

ing of the pressure plate 1 09"is maintained by the;,roller's 137,;FIG. 4., journaled on:pi 1S. 138 fixedlin' the outer e'nds A master brake cylinder 160, FIG. '9, has a fiuidpresthrough line 162, shut ofi? mmerse-and line 164., A pis-v tonf1-65 in the 'master, cylinder is normally. yieldingly urged by a' compression spring 166 tobpp'ose pressure in the pressure chamber 161. 'A piston [rod .p1unger'i167. fixedjto the piston: extends through the. pressure cham-. her and outwardly through a sealed bore 168 and projects into the brake 'fluid].,charnber .169 "which chamber 169, is connectednthrough a common line 17 0v to the brake'cylin der'pressurechambers 55, FIG. 8.- A hand pump: 171

having an operating handlei172 is connected through" a e 173; Check valve 174. and-line 175 ;to ;-the pressure chamber forinitiallytcharging the chamber 169 with brake p fluid so tha'tthe spring 166 acting throughthe piston 165 and plunger 167 applies the proper pressure in the chamber:169 to set thelbrakes 40 for, locking'the frame ZS to the columns ,15'. Ajsuitable gage176'inlin'e 170 indicates if proper braking {pressure being maintained in the brakin'g circuit'170rtegrally connected end members 178 and side rnernbers' 179 having upright corner posts 180;"FIGS'.-13 and- 4. Ground contacting WheelsllSI-IOllilflg on'the flo'or' 's'urface Apallet cart 177 has awe frame: comprising the} in 17, are journaled against axial movement Orr-suitable traverse shafts 182 'fixe'djin the: side; members 178 r-of'the pallet cart} pallet support structure comprising the r V acrossmembers 183-andtheextended-sldelinembers 184 lar rotation by endless crosse cha ns 12,8 ,operatmg over are x to fltheitops e j upnghtncomer g r 1 forma horizontallsurface 185' 'paralleltethe floor surface 17 and the' bottom surface 1179f thefpressure plate 109; A stack carr yingj pallet- 1186fhavin'g a top work-receiving surface 187 parallel to the'sur-face. 117 of the pres sure plate 109 is carried on'the-palletfcart177.

- In'ope'ration': With the frame 23 ans moldb'ox 511a lowered position clamped to the column 15 by brakes 40,

'a hinged end60'is swungup and the ,p;11ercan 177 witha pallet 186 'is moved intoftliemoldbox-57' as shown in 7 FIGS. 4. and S. IThe'sidesQ188 andfends 1896f. the a pallet'186justnice1y fit withi'close clearance within conof the members 139 fixed transversely 'onfthe' outerenglsof the frame members. 134,;the rollers 137 riding" upiand down. gainst the surfaces 14 0jo' f"thevertical corner mem bers22." V I The relative 'vertical. movement of the .frarne..23 andj fines of the inside wallsof sidesv 53xand ends 6013f the 'rnoldbox 57: The hinged. end that has'been open up sto accommodate the palletgca'rt 177 and ipallet'1 86 is swung back down and locked in operativeposition by the,

"clampsf62.' Atthis time'control lever,159f;of valve 153 has been moved-to a positionto apply pressure in the line 158gto"pressure charrrbers' ofcylinders' to hold 4, in step bars 143' fix'edto the supper'tiej barfs 25 b suitable brackets 144. -The upper ends of the rod 141iare I the pressure plate1109 in raised jpositionshown in FIGS; '2 and 3.; Also, at this time, spring 166;FIG. 9, inf-master lbralgeicylinder 16 0 has.push piston 165Qand plunger 167 "intobrake fluid chariiber 169 setting the l'arakes 40'. Level."

108 of control valve 104 is moved to a position to energize cylinder 75 to position the feed drawer 69 on the deck plate 66.

Control lever 159 of valve 153, FIG. 9, is then manipulated to apply pressure in the line 156 into chambers 155 of the cylinders 113 causing pressure plate 109 to move down into the mold box to engage the pallet surface 187 when its downward movement is stopped. Pressure in line 156 then builds up and is transmitted through line 164, valve 163 which is normally left open, the line 162 into pressure chamber 161 of the master brake cylinder 160 pushing piston 165 and plunger 167 to the left against spring 166 relieving pressure in chamber 169 to release the brakes 40.

With the release of the brakes 40 and continued pressure in the chambers 155 of cylinders 113 and pressure plate 109 supported on the pallet 186, the frame 23 is caused to move upwardly on the columns until the thrust nuts and washers 145 engage the top surface 146 of the stop bars 143 of the frame 23, FIG. 4. The position of stopping is such that the distance between the top surface 187 of the pallet 186 and the bottom surface 117 of the pressure plate equal the desired depth of material to be deposited within the mold box 57 for each slab to be formed.

Control lever 159 of valve 153 is then moved to release pressure from line 156, which allows brakes 40 to set holding the frame 23 to the columns 15 and to apply pressure in line 158 to raise the pressure plate to up position, FIGS. 2 and 3, for movement of the feed drawer 69 across the mold box.

A suitable supply of plastic concrete is placed in the feed drawer 69 positioned on the deck plate 66, FIG. 5, and control lever 10% of control valve 104, FIG. 9, is operated to cause the loaded feed drawer 69 to move across the top of the mold box 57 to the deck plate 67 dumping a supply of plastic concrete therein. The control lever 108 is then moved to bring the feed drawer 69 back to the deck 66, screeding off the supply of concrete to the height of the mold box ready for the compacting operation.

The control lever 159 of valve 153 is then operated to apply pressure in line 156 to cause pressure plate 109 to move down against the screeded surface of the plastic cement and into the mold box to compact the supply of cement therein until the pressure in line 156 builds up to a predetermined point whereupon the brakes 40 are released causing the frame 23 to move upwardly the desired thickness of the next slab at the point where the thrust Washers and nuts 145 engage the stop bars 143. Lever 1590f valve 153 is then moved to release pressure in line 156, causing brake 40 to set to hold frame 23 position and to apply pressure in line 158 to raise the pressure plate 109 to up position.

A layer of suitable parting paper or parting sand 191 is then placed on the top surface of the slab 192 in the mold box that has just been formed. The feed drawer is then moved over the mold box placing the next charge of plastic concrete therein and the above described operations repeated until a stack of sandwiched slabs 193 to 198a inclusive, FIG. 6, have been completed, the frame 23 and mold box 57 moving progressively upwardly for each slab formed. When all of the required slabs have been completed, a hinged side 60 is swung open and the pallet cart with the pallet 136 containing the stack of finished slabs thereon is rolled out of the mold box ready for curing and storage.

In certain instances it may be desirable to insert reinforcing mesh or rod 199 intermediate the top 200 and bottom 201 surface of a slab 19249841. To this end there is provided a flipper screed bar 202, FIG. 5 hinged at 203 at the bottom edge of the end 71 of the feed drawer, the width of the screed bar 202 equaling substantially one half the slab to be formed. When the feed drawer 69 is on the deck plate 66 the screed bar 202 is swung up to horizontal position lying on top of the deck 66. As the feed drawer 69 moves off of the deck 66 over the mold box 57 the screed bar 202 drops to a vertical posi tion so as to screed the material in the mold box 57 to half its normal depth, the feed drawer continuing until it moves out over the opposite deck 67 with the screed bar 202 stopping at the edge 204 of the mold Box. Before the feed drawer starts back, mesh or reinforcing rods are laid on the concrete just deposited in the mold box. The feed drawer then moves back across the mold box causing the screed bar 202 to flip up to horizontal position as it comes up over the edge 205 of the mold box, the edge 206 of the mold box 69 screeding further material over the reinforcing to full depth in the mold box to complete the loading thereof for the application of forming pressure by the pressure plate 109. If desired, the above described operation of the screed bar 202 may be affected by suitable cam lever mechanism, not shown, operating in response to the position and movement of the feed drawer.

There has thus been provided a procedure and apparatus in which a pallet 186 is surrounded by a vertically movable mold box 57, in the present example, of rectangular configuration closely fitting around the edges of the pallet 186. A feed drawer 69 traversing across the top edge 63 of the mold box distributes a concrete mixture of suitable consistency, preferably dry-mix of low Water content, into the mold box area above the pallet 186 and screeds the concrete off level with the top edge 68 of the mold box extending above the pallet 186. A pressure plate 109 then presses down on the top of the deposited concrete mixture which is preferably vibrated until a certain degree of settlement, approximately 20%, takes place. Following this, further pressure is applied downwardly on the pressure plate 109 which then causes the frame 23 and the attached mold box around the just east slab 192 to move upwardly to a new location equal to the thickness plus the compaction settlement of the next slab 193 to be cast on top of the already cast slab 192. At this point the frame 23 is automatically locked by the brakes 40 to the supporting columns 15 on the floor surface 17 upon which is carried the pallet cart 177 supporting the pallet 186 and the slab 192-198 being formed. The brakes 40 hold the frame in its raised position so that the new position of the mold box 57 and its top edge above the previously cast slab 192 is maintained. A piece of foil, water impervious paper or parting sand 191 is placed on top of the just cast slab 192 and then the feed drawer is again moved over the mold box and previously cast slab to repeat the above described operating cycle. The above operation continues for the number of slabs 192-198a vertically sandwiched one on top of the other to the desired height and number in a stack as required.

While the apparatus herein disclosed and described constitutes a preferred form of the invention, it is also to be understood that the apparatus is capable of mechanical alteration without departing from the spirit of the invention and that such mechanical arrangement and commercial adaptation a fall within the scope of the appendant claims are intended to be included herein.

Having thus fully set forth and described this invention what is claimed and desired to be obtained by United States Letters patent is:

1. A concrete slab making machine comprising in combination:

(a) a main support fixed to a floor surface,

(b) a frame vertically movable on said main support relative to said floor surface,

(c) releasable locking means on said frame for locking said frame against vertical movement on said main support,

(d) a pallet cart supported on said floor surface,

(e) a pallet carried on said cart,

I (f) a mold box fixed on said f (g) deck plates fixed'on 7 a r) a mold box fixed an said' frame said pallet,

adapted to receive (g) deck plates fixed on said frame and located a op posite ends of said mold box,

,7 (h) a feed drawer supported on said deck plates and said mold box adapted to move back and forth 7 across the top of said mold box from deckplate to deck plate, V r H a a r V (i) power means on said frame for actuating said feed I drawer in said back and forth movements,

(j) a pressure plate mounted for vertical relative move ment on said frame into and out of said moldbox,

(k) power means-interconnected between said frame;

and said pressure plate adapted to relatively vertically reciprocate said pressure plate and said frame; (l) stopmeans on said pressure plate adapted to engage said frame to limit upward ,relative travelofa said frame relative to said pressure plate,

movement of said pressure plate to release saidlocking means to cause upward movement of said-frame relative to said pressure plate. r

2. A 1 concrete slab, making machine comprising-in combination: Y

(a) a main support fixed to a floor surface,

(b) a frame vertically, movable on said'main support said pallet,

7 said frame and located at opposite ends of said mold box, 7

(h) a feed drawer supported Ion said deck plates and said mold box adapted to -move back and forth across the'top of said'rnold'box fromdeck plate to' deckplate," I

(i) power means on said frame for actuating said feed drawer-in said back and forth movements, K a (j) a pressure mounted for. vertical relative movement on said'frame into and outiof said 'mold'box,

'(k)- power "means interconnected between s'aid' frame and said pressure plate ada pted to relatively'verti cally reciprocate said pressure 'plate and said frame, a (1) stop rneans on-said pressure plate adapted wen-4 gage said frametolimit upward relative travel: of said frame relative to'said pressurejplate,

. (m) means actuatedbyrestraining'the downward movea v i w 7 0f, said PESSurePhte-m release said-lockin fwrLLiAM sTEPHENsoNPri'mary Examiner a 7 ALE ANDER; SBRODME WHITE Exah iner's means to cause upward movement Of-said'frame' relative to said pressure plate, said upward movement of said frame being arrested by the operation of said stop meansp V (d) a pallet cart ,10 7 r I a j (f) 'a mold box'fixed on said frame adapted to receive ,(m) means actuated by restraining the downward;

(1)stopmeans on said pressure plate adapted to enjao V deckplate, v r

bination:

(a), a main support fixed toa tloor surface,

j (b) aframe vertic-ally movable on said main support a relative to said floor surface, .7 i v (c) releasable locking means on said frame for locking said frame against vertical movement on said main support, a a

supported on said floor surface,

(e) a pallet carried onsaid cart,

' said pallet,

" (g) deck plates' fixed on said, frame and located at op posite'ends of said mold box,

(h) a feed, drawer supported'on said deck plates and saidimold box adapted to move back and forth across the top ofzsaid rnold box from deck plate to v (i) power means onsaid frame for actuating said feed drawer in said back and forthmovernents, (j) a pressure plate mountedfor verticalrelative move 'ment on said frame into andfout ofrsaid mold box.

' (k) power'meansinterconnected. between said frame 7 and said,1pressure plate adapted to relatively vertically reciprocate-said pressure plate and said frame,

"gage said frame to limitupward irelative travel of H said frame relative tosaid pressure plate,

(m) means actuated byrestrainingthe downward movemerit/of said pressure plate'to release said locking means to cause upward movementof said frame re lative to saidpressure plate,

5 (n and furthermeans adapted to normallyhold said locking meanstin locked condition when said power means for reciprocating said pressure plate is moving said pressure plateunimpeded in' downward and upward vertical movement relative to said frame.

, References Cite dby the Examiner UNITED STATES PATENTS RKEL, (ROBERT F. 

1. A CONCRETE SLAB MAKING MACHINE COMPRISING IN COMBINATION: (A) A MAIN SUPPORT FIXED TO A FLOOR SURFACE, (B) A FRAME VERTICALLY MOVABLE ON SAID MAIN SUPPORT RELATIVE TO SAID FLOOR SURFACE, (C) RELEASABLY LOCKING MEANS ON SAUD FRAME FOR LOCKING SAID FRAME AGAINST VERTICAL MOVEMENT ON SAID MAIN SUPPORT, (D) A PALLET CART SUPPORTED ON SAID FLOOR SURFACE, (E) A PALLET CARRIED ON SAID CART, (F) A MOLD BOX FIXED ON SAID FRAME ADAPTED TO RECEIVE SAID PALLET, (G) DECK PLATES FIXED ON SAID FRAME AND LOCATED AT OPPOSITE ENDS OF SAID MOLD BOX, (H) A FEED DREWER SUPPORTED ON SAID DECK PLATES AND SAID MOLD BOX ADAPTED TO MOVE BACK AND FORTH ACROSS THE TOP OF SAID MOLD BOX FROM DECK PLATE TO DECK PLATE, (I) POWER MEANS ON SAID FRAME FOR ACTUATING SAID FEED DRAWER IN SAID BACK AND FORTH MOVEMENTS, (J) A PRESSURE PLATE MOUNTED FOR VERTICAL RELATIVE MOVEMENT ON SAID FRAME INTO AND OUT OF SAID MOLD BOX, (K) POWER MEANS INTERCONNECTED BETWEEN SAID FRAME AND SAID PRESSURE PLATE ADAPTED TO RELATIVELY VERTICALLY RECIPROCATE SAID PRESSURE PLATE AND SAID FRAME, (L) STOP MEANS ON SAID PRESSURE PLATE ADAPTED TO ENGAGE SAID FRAME TO LIMIT UPWARD RELATIVE TRAVEL OF SAID FRAME RELATIVE TO SAID PRESSURE PLATE, (M) MEANS ACTUATED BY RESTRAINING THE DOWNWARD MOVEMENT OF SAID PRESSURE PLATE TO RELEASE SAID LOCKING MEANS TO CAUSE UPWARD MOVEMENT OF SAID FRAME RELATIVE TO SAID PRESSURE PLATE.. 